# Docker Build & Push Pipeline
# Multi-platform build with caching and security scanning

name: Docker Build

on:
  push:
    branches: [main]
    tags: ['v*']
  pull_request:
    branches: [main]

env:
  REGISTRY: ghcr.io
  IMAGE_NAME: ${{ github.repository }}

jobs:
  build:
    name: Build & Push Docker Image
    runs-on: ubuntu-latest
    timeout-minutes: 30

    permissions:
      contents: read
      packages: write
      security-events: write  # For uploading SARIF

    steps:
      - uses: actions/checkout@v4

      - name: Set up QEMU
        uses: docker/setup-qemu-action@v3

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Log in to Container Registry
        if: github.event_name != 'pull_request'
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=sha,prefix={{branch}}-

      - name: Build and push Docker image
        id: build
        uses: docker/build-push-action@v5
        with:
          context: .
          platforms: linux/amd64,linux/arm64
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max

      - name: Run Trivy vulnerability scanner
        uses: aquasecurity/trivy-action@master
        with:
          image-ref: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.meta.outputs.version }}
          format: 'sarif'
          output: 'trivy-results.sarif'
          severity: 'CRITICAL,HIGH'

      - name: Upload Trivy results to GitHub Security
        if: always()
        uses: github/codeql-action/upload-sarif@v3
        with:
          sarif_file: 'trivy-results.sarif'

      - name: Run Grype vulnerability scanner
        uses: anchore/scan-action@v3
        with:
          image: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.meta.outputs.version }}
          fail-build: true
          severity-cutoff: high

      - name: Generate SBOM
        uses: anchore/sbom-action@v0
        with:
          image: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.meta.outputs.version }}
          format: spdx-json
          output-file: sbom.spdx.json

      - name: Upload SBOM
        uses: actions/upload-artifact@v4
        with:
          name: sbom
          path: sbom.spdx.json

  sign:
    name: Sign Container Image
    runs-on: ubuntu-latest
    needs: build
    if: github.event_name != 'pull_request'

    permissions:
      contents: read
      packages: write
      id-token: write

    steps:
      - uses: actions/checkout@v4

      - name: Install Cosign
        uses: sigstore/cosign-installer@v3

      - name: Log in to Container Registry
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Sign the images
        env:
          DIGEST: ${{ needs.build.outputs.digest }}
        run: |
          cosign sign --yes ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}@${DIGEST}

  deploy:
    name: Deploy to Kubernetes
    runs-on: ubuntu-latest
    needs: [build, sign]
    if: github.ref == 'refs/heads/main'
    environment:
      name: production
      url: https://example.com

    steps:
      - uses: actions/checkout@v4

      - name: Configure kubectl
        uses: azure/k8s-set-context@v3
        with:
          method: kubeconfig
          kubeconfig: ${{ secrets.KUBE_CONFIG }}

      - name: Deploy to Kubernetes
        run: |
          kubectl set image deployment/myapp \
            myapp=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.sha }} \
            --record

      - name: Verify deployment
        run: |
          kubectl rollout status deployment/myapp --timeout=5m

      - name: Run smoke tests
        run: |
          POD=$(kubectl get pod -l app=myapp -o jsonpath="{.items[0].metadata.name}")
          kubectl exec $POD -- curl -f http://localhost:8080/health